Yarn-covering machine

ABSTRACT

A hollow spindle for the passage therethrough of a yarn to be covered, (herein referred to as the core), by another, (herein referred to as covering filament). The driving spindle of this invention is about double the length of a conventional spindle and it has an irreducibly small diameter. The covering filament is wound in the form of a long, small-diameter, cylindrical cake directly onto the spindle instead of on a bobbin which is mounted on the driving spindle. The spindle is rotated at a rate of speed about three times the rate attainable by conventional machines of this type. The spindle is mounted for quick and easy removal and replacement and in a manner such that, replacing an empty spindle with a loaded one will not disturb the closely spaced spindles of a multispindle installation.

United States Patent [72] Inventor James J. Purcell Wyomissing, Pa. [2!] Appl. No. 809,716 [22] Filed Mar. 24, 1969 [45] Patented May 4, 1971 [73] Assignee Sheer Elastic Corporation [54] YARN-COVERING MACHINE 3 Claims, 9 Drawing Figs.

[52] US. Cl 57/18, 57/ 160 [51] lnt.Cl D02g 3/28, D02g 3/38 [50] Field ofSearch 57/3,6,7, l7, l8, 160

[5 6] References Cited UNITED STATES PATENTS 1,726,099 8/ 1929 Chisholm 57/7X vPrimary Examiner-Donald E. Watkins Attorney-Necho and Kimmelman ABSTRACT: A hollow spindle for the passage therethrough of a yarn to be covered, (herein referred to as the core), by another, (herein referred to as covering filament). The driving spindle of this invention is about double the length of a conventional spindle and it has an irreducibly small diameter. The covering filament is wound in the form of a long, small-diameter, cylindrical cake directly onto the spindle instead of on a bobbin which is mounted on the driving spindle. The spindle is rotated at a rate of speed about three times the rate attainable by conventional machines of this type. The spindle is mounted for quick and easy removal and replacement and in a manner such that, replacing an empty spindle with a loaded one will not disturb the closely spaced spindles of a multispindle installation.

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PATENTEUMAY 4197:

v sum 2 OF 2 MWEVTOK J. PURCELL JAMES YARN-COVERING MACHINE THE BACKGROUND As far as I am aware, it has heretofore been the practice to wind the covering filament, in the form of a cake, over a bobbin which was 3 or 4 inches long and had a diameter of about 2 inches. The loaded bobbin was mounted on a driving spindle which had a diameter of about 1 inch. This meant that, by the time enough yardage was wound on the relatively short bobbin to make an economically feasible run, the outside diameter of the cake (at the beginning of the covering operation, that is, before any substantial yardage had been paid out), will be too large to permit rotation of the bobbin at a rate much in excess of 16,000 r.p.m. This limitation is imposed by the fact that at higher speeds, the centrifugal force acting on the filament as it leaves the bobbin will excessively billow the filament and will subject it to excessive tension. Excessive billowing is undesirable, especially in closely spaced multibobbin installations, and excessive tightness of the wrapping of the covering filament on the core yarn is also undesirable. Also, since the effective centrifugal force decreases as the outside diameter decreases, it follows that, as the operation proceeds, the covering filament will be subjected to progressively decreasing centrifugal force. To vary the speed of rotation as the diameter of the filament cake decreases is too complex and costly to be practical. Actual timing shows that, at 16,000 r.p.m., it takes about 275 hours of running time to use up 1 pound of 20-denier spandex," or comparable filament.

Conventionally, the driving belt was engaged with a pulley which was carried by the driving spindle which carried and rotated the filament-carrying bobbin. Because the pulley has a larger diameter than the spindle, the speed of rotation of the spindle was less than that which could be obtained if the spindle was engaged with the belt directly.

Because the core to be covered passes through the spindle, it must be cut to permit replacement of an empty bobbin with a loaded one, and it must be rethreaded through the spindle after the loaded bobbin has been placed in position on its spindle. Because the spindles were not easily mounted or demounted, the rethreading had to be done in sito. This was done by passing a special hook downwardly through the spindle, securing the end of the core yarn to the lower end of hook and pulling the core yarn upwardly through the spindle. Actual experience shows that, even for a skilled operator, this task is tedious and time consuming.

THE INVENTION In a device embodying the invention, the relatively short and large-diameter bobbin is discarded altogether and the covering filament is wound, in the form of a relatively long, slender cylindrical cake, directly on to the driving spindle. By this arrangement, a pound of covering filament will be about 3 or 4 inches longer, but it will also be correspondingly more slender than a cake having the same yardage but wound on a 3- or 4-inch bobbin. Also, the omission of the bobbin further reduces the outside diameter of the cake. Further, according to this invention, the spindle is driven by direct contact with the belt, i.e., without the interposition of a pulley, and it is mounted for easy removal without disturbing the driving belt or the adjacent spindles.

IN THE DRAWINGS FIG. 1 is a fragmentary and diagrammatic view of a portion of a yarn-covering machine embodying this invention.

FIG. 2 is a top plan view looking in the direction of line 2-2 on FIG. 1.

FIG. 3 is an enlarged sectional view looking in the direction ofline 3-3 on FIG. 1.

FIG. 4 is an enlarged view, partly in section and partly in elevation of the area bracket with broken line 4 in FIG. 1.

FIG. 5 is an enlarged sectional view looking in the direction of line 5-5 of FIG. 4.

FIG. 6 is a sectional view looking in the direction of line 6-6 on FIG. 5.

FIG. 7 is a sectional view looking in the direction of line 7-7 on FIG. 4.

FIG. 8 shows the appearance of a yarn covered by the conventional dry process.

FIG. 9 is similar to FIG. 8 and shows the appearance of a yarn covered by the wet process of this invention, or in the presence of sufficient humidity.

In carrying out my invention, I dispense with the bobbin altogether, and I wind the covering filament 10 directly on spindle 12. Also, I make the spindle about twice the length of a conventional bobbin and I give it a very small outside diameter. In practice, the invention has been successfully carried out by using a spindle about 8 inches long and of about fiveeighths of an inch outside diameter. By this arrangement, the outside diameter of the cake, measured at the point at which the filament leaves the spindle, is reduced to an extent which permits rotation of the spindle at 52,000 r.p.m. to 53,000 r.p.m. without developing enough centrifugal, force to billow the filament excessively, or excessively to tension the filament as it is wound over the core yarn. By this, the first step of my invention, I save the cost of providing and of handling the bobbins, and I wind a given yardage of filament into a relatively long, substantially cylindrical cake 14, which has a much smaller diameter than it would have were the same yardage wound on a bobbin only 3 or 4 inches long. By this arrangement, the centrifugal force developed at 52,000 r.p.m. will not materially billow, or undesirably tension the filament. Further, the difference between the outside diameter of a full filament cake l4 and the outside diameter of the bare spindle is relatively small and, therefore, the drop in the centrifugal force exerted on the filament as it leaves the spindle, that is, the difference between the force exerted on the filament when the filament cake is at its maximum diameter, and the force exerted on the filament after a substantial portion thereof has been paid out, will be relatively small. This makes for greater uniformity of the centrifugally induced billowing and tension.

As a second step in carrying out my invention, I do away with the pulley which, conventionally, is carried by the spindle and is engaged with the driving belt 16, and l engage the spindle directly with the driving belt as best shown in FIGS. 1, 2 and 3. By this arrangement, the speed of rotation of the spindle will not be reduced by the pulley. On the contrary, the speed of rotation of the spindle will be substantially proportional to the speed of the belt.

The third step in my invention, is to make every spindle readily detachable from the supporting frame 18 and from the driving belt 16, without, in any way, disturbingthe belt or any of the other spindles. This is done by providing the spindle with a threaded sleeve 20 which contains conventional antifriction bearings 22, and is provided with a shoulder 24 which coacts with a nut 26, detachably to clamp the spindle to the frame 18. It will be noted that the spindles are driven by engagement with the outer face 32 of endless belt 16 which is driven by the pulleys 30 and 31. By this arrangement, a spindle, with or without core 28 passing therethrough, can easily be disengaged from supporting frame 18 and moved out of contact with the driving belt, and vice versa. This is an important feature of the invention because it makes it possible to pass the core through the spindle at a suitably equipped workbench instead of having to reach in between closely spaced and hardly accessible spindles.

Conventionally, the filament is subjected to tension so as to wrap it tightly about the core and so as to straighten out the kinks. I have discovered that tension sufficient to insure proper covering will not remove the kinks, and the product will look as exaggeratedly. and diagrammatically shown in FIG. 8.

The fourth step of my invention, therefore, is to provide a manifold 34 having nozzles 36 for spraying the core and the filament with steam, or other agent, so that the finished product will have a smoother appearance; again, as exaggeratedly and diagrammatically shown in FIG. 9.

In a prototype tried under actual working conditions, the spindle was rotated at between 52,000 and 53,000 r.p.m., as

compared with l6,000 r.p.m., without any centrifugal forceinduced, ill effects. This increased r.p.m. correspondingly decreased the covering time. This reduction is in addition to the reduction in threading time which, as above set forth, is made possible by the detachable mounting of the spindles on the supporting frame and by engaging the spindle with outer side of the driving belt.

In the prototype referred to above, no filament-tensioning device was used, but this does not preclude the addition of a conventional tensioning device should the demands of a particular run require it. If used, the tensioning device will be applied to the filament as it unwinds from its spindle or after leaving the spindle and before reaching the core 28 to be covered.

lclaim:

l. The method of covering a core yarn with a filament, said method including:

the step of passing the core yarn through a relatively long spindle having a relatively small outside diameter,

winding the covering filament on the spindle in the form of a long, slender cake,

detachably mounting the spindle on a frame for ready and easy removal and replacement, and

engaging one end of the spindle directly with the outer side of an endless driving belt.

2. The method of covering a core yarn with a filament, said method including:

the step of passing the core yarn through a relatively long spindle having a relatively small outside diameter,

Winding the covering filament on the spindle in the form of a long, slender cake,

detachably mounting the spindle on a frame for ready and easy removal and replacement,

engaging one end of the spindle directly with the outer side of an endless driving belt, and

the step of detaching the spindle from the frame and moving the spindle from the vicinity of the frame for threading the core yam therethrough.

3. In combination,

a supporting frame,

an elongated, cylindrical spindle for receiving a covering filament cake wound directly thereon,

means detachably securing said spindle to the frame,

an endless driving belt, and

means mounting said belt in a position for engagement of the outside of the belt with said spindle. 

1. The method of covering a core yarn with a filament, said method including: the step of passing the core yarn through a relatively long spindle having a relatively small outside diameter, winding the covering filament on the spindle in the form of a long, slender cake, detachably mounting the spindle on a frame for ready and easy removal and replacement, and engaging one end of the spindle directly with the outer side of an endless driving belt.
 2. The method of covering a core yarn with a filament, said method including: the step of passing the core yarn through a relatively long spindle having a relatively small outside diameter, winding the covering filament on the spindle in the form of a long, slender cake, detachably mounting the spindle on a frame for ready and easy removal and replacement, engaging one end of the spindle directly with the outer side of an endless driving belt, and the step of detaching the spindle from the frame and moving the spindle from the vicinity of the frame for threading the core yarn therethrough.
 3. In combination, a supporting frame, an elongated, cylindrical spindle for receiving a covering filament cake wound directly thereon, means detachably securing said spindle to the frame, an endless driving belt, and means mounting said belt in a position for engagement of the outside of the belt with said spindle. 